Support fixtures are used to support substrates, such as, for example printed circuit (PC) boards, during their manufacture. Many PC boards include chips, resistors, and other elements on both sides of the board, which are typically installed a first side of the board, and then on an opposing side of the board. After these elements have been inserted on the first side of the board, the board is flipped over and supported by the first side. Support members on the support fixture project away from the base of the support fixture and engage the elements and the board, thereby supporting the board so that additional elements can be installed on the second side of the board.
Several patents disclose support fixtures with independently movable support members to engage board elements and boards, such as, for example, U.S. Pat. No. 6,702,272, which uses a ball to lock a respective pin in a desired support position. This fixture requires a complex sequence of low pressure air, high pressure air, and vacuum to set the support members, and then release the support members to reset the fixture. Additionally, the force applied by the ball to the pin may not always be sufficiently high enough to maintain the pin in its desired support position when a board element is placed onto the pin.
It would be beneficial to provide a board support fixture that requires a less complex sequence of operation to set and then reset the fixture, as well as a fixture that applies a higher force to each pin to ensure that the pin is maintained in its desired support position while the PC board is being worked on.